This invention relates to smoking articles such as cigarettes, and in particular to smoking articles having filter elements attached thereto.
Popular smoking articles such as cigarettes have a substantially rod shaped structure and include a smokable material such as strands of tobacco surrounded by a wrapping material such as paper thereby forming a tobacco rod. It has been desirable to provide cigarettes having cylindrical filters positioned at one end thereof. Typically, filters are constructed from fibrous materials such as cellulose acetate and are attached to the tobacco rod using tipping material.
Known cigarette filter elements generally have a white color, and upon use of the cigarette such filter elements can undergo a noticeable discoloration. In particular, cigarettes having filter elements which resemble hollow tubes (e.g., as proposed in U.S. Pat. No. 3,703,429, West German Pat. No. 2,107,850, and Japanese Patent Application No. 59-196,082) can undergo an unsightly discoloration within the visible inner region of the tube.
In view of the fact that conventional cigarette filter elements tend to exhibit unsightly discoloration during use of cigarettes containing such elements, it would be highly desirable to provide a cigarette filter region which exhibits a low amount of visible discoloration upon use.